On Wednesday 31 October 2001, at about 0800, Air National Chieftain ZK-RDT, operating as Origin 457, was on a scheduled passenger flight from New Plymouth to Auckland when the cabin door opened in flight. Passengers held the door in a slightly ajar position for about 10 minutes while the aeroplane was landed at Auckland.
The incident resulted from wear and distortion of door latch components, which had not been detected and rectified.
A safety issue identified was the need for more awareness by both pilots and engineers of mechanical deterioration of items such as the door latch mechanism
